Current limitations of biodegradation screening tests and prediction of biodegradability: A focus on fragrance substances

The outcome of the analyses of this study underlines the need to take into account results from OECD screening tests that are best adapted to physico-chemical properties of fragrances (hydrophobicity, volatility and inhibition potential at high test concentration) and conducted at reduced stringency compared to OECD guidelines (extended incubation owing to reduced bioavailability). Negative MITI database results should be critically reviewed, particularly for quaternary carbon-containing compounds. For future efforts aimed at designing more environmentally benign chemicals, the apparent underestimations will have to be overcome by providing more realistic experimental data that should subsequently be used to improve current biodegradation prediction models for better guidance.